title: An in-vitro animal experiment on metal implants' thermal effect on radiofrequency ablation.
abstract: BACKGROUND
  To explore metal implants' thermal effect on radiofrequency ablation (RFA) and ascertain distance-thermal relationship between the metal implants and radiofrequency (RF) electrode.
  
  
  METHODS
  Metal implants models were established in seven in-vitro porcine livers using silver clips or 125I seeds. RFA were conducted centering the RF electrode axis1 cm away from them, with one side containing a metal implants model the test group and the other side the control group. The thermometric needles were used to measure multi-point temperatures in order to compare the time-distance-temperature difference between the two groups. The gross scopes of the ablation of the two groups were measured and the tissues were analyzed for microscopic histology.
  
  
  RESULTS
  At the ablation times of 8, 12, and 15 min, the average multi-point temperatures of the test group and the control group were 48.2±18.07°C, 51.5±19.57°C, 54.6±19.75°C, and 48.6±17.69°C, 52.2±19.73°C, 54.9±19.24°C, respectively, and the differences were not statistically significant (n=126, P>0.05). At the ablation times of 12 and 15 min, the ablation scopes of the test group and the control group were (horizontal/longitudinal diameter) 1.55/3.48 cm, 1.89/3.72 cm, and 1.56/3.48 cm, 1.89/3.72 cm, respectively, and the differences were not statistically significant (n=14, P>0.05). The two groups had the same manifestations in microscopy.
  
  
  CONCLUSIONS
  Metal implants do not cause significant thermal effect on RFA.
authors.affiliation: Minimally Invasive Interventional Treatment Center, Shenzhen People’s Hospital, Shenzhen, Guangdong, People’s Republic of China.
authors.forename: Zhen-Wen
authors.initials: ZW
authors.lastname: Lin
authors.forename: Hong
authors.initials: H
authors.lastname: Chu
authors.forename: Fan
authors.initials: F
authors.lastname: He
authors.forename: Lu-Ping
authors.initials: LP
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Kong
mesh_terms: D000818:Animals; D001831:Body Temperature; D017115:Catheter Ablation; D004566:Electrodes; D066298:In Vitro Techniques; D008099:Liver / Q000473:pathology / Q000601:surgery*; D008670:Metals; D023421:Models, Animal; D019736:Prostheses and Implants; D013552:Swine
chemical_list: D008670:Metals